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This chapter lists some ineffective or even possibly harmful procedures and products that are marketed to "kill mold" or "prevent mold" - things that you should avoid any time, including when cleaning a building after it has been flooded. Our photograph shows an extensive toxic black mold reservoir in a New York City high rise apartment. Sprays, fogging, or ozone would be ineffective remedies for this problem.

If your building has been flooded, this website provides an easy to understand guide for flood damage assessment, setting priorities of action, safety, and we provide special information about avoiding or minimizing mold damage.

Our Flood Response Checklist lists key actions you should take after building flooding to minimize mold damage, and includes some safety warnings. We also list after-flood "anti-mold" procedures that do not work or are unsafe - to help you avoid unnecessary expense in dealing with mold after a building flood. If your building is already moldy or if you suspect mold related illness in your building, we link to a step by step Mold Action Guide dealing with toxic or allergenic indoor mold and other indoor contaminants: when and how to inspect or test for mold, when to hire an expert, how to clean up a moldy area, when and how to perform post-remediation mold testing. If your septic system has been flooded we link to an article outlining what to do about that system as well. Extensive, technically detailed in-depth articles on other mold detection, testing, and prevention methods are organized at our Mold Information Center

© Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

INEFFECTIVE PRODUCTS or Unreliable Products and Procedures Sold for Removing Mold, Cleaning Off Mold, or for Preventing Mold Growth

• Disinfectants, mold biocides, mold killing sprays, mold washes, & fungicides: Spraying cleaners, disinfectants, bleach, fungicides can be used to clean a moldy surface if you wish, and where bacterial contamination is present or suspected they are appropriate. But do not use sprays or disinfectants without first drying the building and removing sludge, debris, and contaminated or moldy materials and then physically leaning all surfaces.
  
  Use of disinfectants or biocides as part of cleaning are appropriate at times, especially where there has been or may have been sewage backup where bacterial contamination is present. But no spray or gas is an effective substitute for physically cleaning and physically removing mold and moldy materials. Watch out for companies who offer sprays or gases as a shortcut when cleaning is what's needed. A dead mold spore can still be toxic or allergenic. Clean off the mold from hard surfaces, and throw away moldy materials that cannot be cleaned.
  
  See SEWAGE CONTAMINATION IN BUILDINGS for discussion of how to test for and remove sewage contaminants from buildings.
  
  See MOLD CLEANUP GUIDE- HOW TO GET RID OF MOLD for advice on using bleach or other cleaners to remove mold from surfaces.
• Ozone for mold: Using ozone generators to "kill" mold. See Ozone Warnings - Use of Ozone as a "mold" remedy is ineffective and may be dangerous.
• Dehumidification without Demolition Water "extraction" methods which simply run dehumidifiers in a building which has been flooded. we have found soaking wet wall cavities and insulation many weeks after a building appeared "dry" when this method was used.
• Blown-air Wall Cavity Treatments: "Water extraction" methods that cut small holes between wall studs to blow air through the wall cavity. In many buildings which we have investigated where this method was used, we found severe mold growth on the cavity side of drywall and wallboard afterwards.
• Water Detection to Track Moldy Areas: Use of moisture meters or infra red or other measures to "find the wet areas" - this works to find mold-risk areas only if the cavities are still wet. In other words, if a building was wet in the past but has since dried, it could have a severe hidden mold infection that will not be detected by using moisture-detection methods.

INEFFECTIVE METHODS Used to Detect Mold in Buildings

• Air sampling to screen buildings for mold: is useful but unreliable. We have documented very high variation in the level of airborne particles in buildings over very short time intervals, as little as over a few seconds. We have documented very high variation in the level of airborne particles in buildings depending also on how and exactly where the sample is collected, and depending on changes in building conditions.
  
  Opening a basement door, turning on a fan, moving the air sampler from the floor to a table, can produce completely different results. Furthermore, even if we do detect evidence of problem mold in an air sample we do not know where it's coming from, how big the mold reservoir is, what caused it, or what level of cleanup is needed.
  
  Is the mold just from a single pool table in the basement? Or is all of that clean-looking insulation mold contaminated. Air sampling is a useful tool but not a reliable building screen for mold when used alone and without a very thorough visual inspection and application of good building science.
  
  See Validity of Air Samples as Mold Tests to characterize indoor air and the limitations of this method, and also see INDOOR AIR QUALITY METHODS COMPARED for additional details.
• Culture tests for mold are, we're sorry to say, junk science, though they're fun to look at. See Validity of Cultures (settlement plates or swabs) to find toxic mold in buildings for details.
• Thermal scans and infra-red devices to find mold in buildings: the use of IR or thermography is effective in finding places where building temperature varies for any reason: missing insulation, wet insulation, electrical failures, radiant heat system failures.
  
  IR and thermography are wonderful tools. But these tools can only detect a building condition that is present at the time that the tool is used. As with our moisture detection schemes above, if a building wall was flooded and its insulation soaked last year, the wall cavity may be mold-contaminated, but having since dried, the thermal scan method will not detect that condition.
• MVOC-detection, mold related volatile organic compounds to find mold in buildings: are limited in effectiveness. As we discuss below at mold-sniffing dogs, not all molds produce MVOCs and MVOCs are also not produced consistently even when the mold species can make these gases. See Sampling for gases for details about MVOC detection.
• Mold sniffing dogs used to find mold in buildings: are not a joke to everyone. Some mold investigators use dogs trained to respond to mold odors - usually gases produced by MVOC's. There are some fatal limitations to mold sniffing dogs that prevent an expert from taking them seriously, even if the dogs may be the cutest and most fun mold detection device around.
  • Spores or MVOCs may be absent: Allergenic or toxic molds may be present but may not be producing MVOCs or other materials that the dog senses. Not all molds produce gases and smells; even if a mold species does produce detectable MVOCs the mold colony does not always actively do so. Spore release from a mold colony and gas production from mold varies widely over time as a function of changes in the building environment: moisture, temperature, light exposure, air movement and other factors can "turn on" or "turn off" these effects. So our cute beagle mold sniffer may not sense a problem even though one is present.
  • Most mold sniffing dogs can't write a remediation plan. Even if a mold sniffer dog does suspect a mold problem in a building and tells his handler of it, that's not enough data to act upon. We do not know the size, location, or cause of the mold contamination; we do not know if the mold our molddog found was the only or even the most important mold reservoir.
  • Most mold sniffing dogs are short: not many of them can poke their noses in all of the areas where mold problems are most likely such as high on building walls, along building ceilings, across attic insulation, etc. People who describe the mold sniffing dog service to us have all confirmed that not once did the mold detection dog's handler pick up the dog and lift it into the air so that the dog could thoroughly explore all of the building's ceilings, nor did these critters crawl through attic insulation.
  • Mold sniffing may be hazardous to the dog's health. We have been collecting data for two decades showing that some pets become sensitized to and very ill from exposure to some molds. Some of them have died. It's not good for the dog to keep going into moldy buildings - and if the dog wore a dog-fitted HEPA respirator it's doubtful s/he would smell building conditions very accurately.

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Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP A Guide to Mold Cleanup Procedures
  FLOODS & MOLD CLEAN/PREVENT A Guide to Dealing with Flood Damage & Mold Prevention &r Cleanup of Flooded Homes
  FIRST PRIORITIES When Responding to a Flooded Building
  BUILDING ENTRY PROCEDURE How to Enter a Building After a Building Flood
  DRINKING WATER - EMERGENCY PURIFICATION How to purify emergency drinking water, how to remove odors
  DRINKING WATER - EMERGENCY SOURCES Where to find drinking water in an emergency
  ELECTRICAL SAFETY for Flood Damage Inspectors
  Foundation Inspection for Flood Damage
  FLOOD RESPONSE CHECKLIST Checklist of Key Steps to Minimize Mold Damage After a Building Flood
  INEFFECTIVE MOLD PRODUCTS Ineffective Mold Products and Procedures to Avoid in Mold Cleanup/Prevention
  FURTHER STEPS PREVENT MOLD Further Steps to Avoid Mold Damage After a Building Flood
  WHEN TO STOP LOOKING FOR MOLD after Flooding: When is a Mold Cleanup Job Complete?
  GENERAL MOLD PREVENTION Preventing Future Mold After a Flooded Building Cleanup
  FLOOD DAMAGE RFERENCES References on Mold Prevention and Flood Damage
  FLOOD VENTS How to Use Flood Vents for Structural Protection from Flooding - Flood Venting in Foundations and Enclosures Below Design Flood Elevation
  SEPTIC SYSTEMS & FLOODS What to Do after a Flood - Septic Flood Response, Safety, Health, Maintenance, Repair Advice
  SEWAGE CONTAMINATION IN BUILDINGS how to detect and respond to sewage backups
  SEWAGE PATHOGENS in SEPTIC SLUDGE what are the contaminants in sewage
  Wind Damage to Roofs how to assess and identify wind damage to roofs

• Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. (727) 595-4211 mark@BestTampaInspector.com 11/06
• Hankey and Brown home inspectors, Eden Prairie, MN, technical review by Roger Hankey, prior chairman, Standards Committee, American Society of Home Inspectors - ASHI. 952 829-0044 - hankeyandbrown.com 11/06
• Arlene Puentes, a licensed home inspector, educator, and building failures researcher in Kingston, NY. 11/29/06
• Technical reviewers are invited to comment or ask questions - contact us.

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